Toward Heterolytic Bond Dissociation of Dihydrogen: The Study of Hydrogen in Arsenolite under High Pressure

The discovery of arsenic(III) oxide hydrogen inclusion compound As4O6·2H2 formed under high pressure is presented. Synchrotron X-ray diffraction experiments and DFT computations permit for a proposal of the compound’s structural model, whereas Raman scattering experiments reveal significant softening of H–H stretching mode. This is attributed to the onset of heterolytic H–H bond dissociation induced by hydrogen interactions with arsenic(III) lone electron pairs based on ICOOP and ICOHP computational studies.